The present invention relates generally to the biological and chemical arts. In particular, the present invention is directed to compositions and methods useful in qualitative and quantitative assays of compounds of interest in the chemical and biological arts.
A wide variety of techniques have been developed for determining the concentration of one or more compounds (generally referred to as analytes) in a liquid sample. In many of these methods, use is made of antibodies or fragments thereof which bind specifically to the analyte. In particular, antibodies bound to a solid support have been employed in a variety of sandwich-type and competitive assays.
While the use of antibodies or fragments thereof has the distinct advantage of the specificity of these reagents for the target analytes, there are nonetheless significant disadvantages with the heretofore-known assay systems. For example, when antibody is bound to a solid support, reaction between antibody and analyte can only occur in a heterogeneous immunochemical reaction; it is well known, however, that the kinetics of such reactions in a homogeneous solution phase are much more favorable. In addition, antibody bound to a solid support is often not reusable for a plurality of assays. Further, for each specific analyte it is necessary to provide a unique product comprising antibody bound to solid support. It would clearly be advantageous to provide assay systems wherein a solid support component could be used in a variety of different assays and could be reused without loss of effectiveness.
It is an object of the present invention to provide novel assay methods and compositions for use therein which do not suffer from the drawbacks of the prior art methods and compositions.